Toolhead for a shaping machine

ABSTRACT

The invention concerns a tool head for shaping machine designed to machine the side segments of tree trunks. The tool head has a rotationally driven main body (1) with several groups of chipper blades (2, 3) round its circumference. The front chipper blade (2) in each group and a front-mounted finishing tool, e.g. a segment (4) of a circular-saw blade, are mounted on a common tool carrier (5). The tool carrier (5) is detachably attached to the tool-head main body (1) and is held in place by clamps (16). If, as a result of wear, it becomes necessary to replace a tool, the tool carrier is replaced after the clamp (16) has been loosened.

BACKGROUND OF THE INVENTION

The invention relates to a toolhead for a profile machining tool formachining the lateral segments of logs having a rotationally-driventoolhead main body with a plurality of chopping teeth groups on itsperiphery and at least one planing tool on its face, wherein each groupof chopping teeth exhibits at least one chopping tooth on the face.

Profile machining tools of this type are known (e.g. DE 3038566 C2).They remove lateral segments from logs that are unworked or evened ontwo sides, wherein the chopping teeth of the toolhead produce productchips. A planing tool mounted on the face of the toolhead and oftencomprising circular saw segments, a circular saw ring, or planing teethfinishes the surface generated on the log. The planing tool can beplaced so that it cuts before or after the adjacent chopping tooth,designated here as a "face chopping tooth." Preceding planing teethprevent any cracks originated from the face chopping tooth fromextending down into the remaining wooden surface. Succeeding planingteeth finish the relatively uneven wooden surface generated by the facechopping teeth.

Due to the unavoidable wear, the planing teeth and chopping teeth mustbe replaced regularly. The relatively long associated downtime is amajor disadvantage of such toolheads.

One known toolhead of this type (DE 28 50 263 A1) uses a replaceableplaning tool fastened to the toolhead main body. However, the choppingteeth and especially the wear-prone face chopping teeth must still bereplaced individually.

Thus, it is the object of the invention to configure the toolhead of thetype cited in the beginning such that the downtimes necessitated byunavoidable tool wear are greatly reduced.

SUMMARY OF THE INVENTION

This object is accomplished according to the invention by attaching boththe face chopping tooth and the planing tool to a common toolholder,which is replaceably fastened to the toolhead main.

Hence, replacement of the planing tools and the face chopping teeth ineach group of chopping teeth is much simpler and easier. It issufficient to detach the toolholder from the toolhead main body andexchange the toolhead for a new toolholder having pre-adjusted toolssuch that an adjustment of the tool cutting edges in their mounted stateon the toolhead is no longer necessary. The required downtime can bereduced to a few minutes so that tool change can be performed with onlyslight interruption during a current shift as well as at the end of ashift.

In this connection, experience showing that the planing tools and theface chopping teeth are the most wear-prone tools due to their constantengagement on every occurring log shape was used in the invention. Incontrast, the chopping teeth further removed from the face axially arenot in constant engagement, so they wear considerably less. Hence, theseadditional chopping teeth can be fastened directly to the toolhead mainbody.

Depending on the embodiment of the planing tools, the toolholder can bea ring segment or a ring. If circular saw segments, to which arespective group of chopping teeth is usually allocated, are used asplaning tools, then it is advantageous to embody the toolholder as aring segment bearing the face chopping tooth on its forward end andbearing the circular saw ring segment on its face as a planing tool.

If, however, the planing tool is embodied as a circular saw ring, it ispractical to embody the toolholder as a ring as well.

A particularly preferred embodiment of the invention provides that thetoolholder is fastened to the toolhead main body by means ofquick-tensioning devices. These devices allow especially quick toolchange so that required machine downtime can be reduced quitesubstantially.

The quick-tensioning device preferably has at least one tensioning pinprotruding from and parallel with respect to axis to the toolholder andextending into a tensioning hole of the toolhead main body and hereinrespectively in engagement with a tensioning apparatus.

An especially favorable construction provides that the tensioning pinsare also centered in the tensioning holes.

Rather than using quick-tensioning devices, it is also possible to screwthe toolholder directly to the toolhead main body. This construction issimpler than using a quick-tensioning device and still keeps toolchanges relatively brief.

BRIEF DESCRIPTION OF THE DRAWING

The invention is described below by way of example with reference toexemplary embodiments illustrated in the figures. Shown are

FIG. 1 a toolhead of a profile machining tool in three-dimensionalrepresentation, showing one of the toolholders in a detached state and acentral guide disc of the toolhead being omitted to simplify thedrawing;

FIG. 2 an enlarged detail of a radial cross-section of the toolhead inaccordance with FIG. 1 with an attached activating mechanism for aquick-tensioning device, and

FIGS. 3 and 4 modified specific embodiments in respective detail ofradial cross-sections in accordance with FIG. 2.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

The toolhead of a profile machining tool depicted in FIG. 1 has on itsperiphery a substantially tapered toolhead main body 1 connected to aprimary shaft (not shown) and bearing tools for machining product chipsfrom the lateral segments of a log moving along the toolhead. Threegroups of three chopping teeth 2 and 3, respectively, are attached tothe periphery of the toolhead, wherein each group comprises a facechopping tooth 2 and two additional chopping teeth 3 staggered at anaxial distance.

Three circular segment saw ring elements 4 are attached to the toolheadand function as planing tools to finish the created wooden surface.

A face chopping tooth 2 of each group and its respective circular sawring element 4 are attached to a common toolholder 5, which is embodiedas a ring segment in the specific embodiment depicted. Toolholder 5 isattached to the face of a front side 1a of toolhead main body 1 and isdetachable and replaceable. In place of the embodiment depicted,toolholder 5 can also be embodied as a ring.

As shown in FIG. 2, toolholder 5 is fastened to toolhead main body 1 bymeans of quick-tensioning devices 6. On each toolholder 5, twotensioning pins 9 oriented parallel with respect to an axis 7 ofrotation of the main body 1 are mounted to respective holes 8 runningparallel to the rotational axis 7 of the toolhead, and each tensioningpin is fastened to toolholder 5 via a flange 10 by means of screws 11.The threads of fastening screws 12 for securing the saw ring segments 4are screwed into respective tensioning pins 9.

Both tensioning pins 9 of each toolholder 5 extend into face tensioningholes 13 of tool holder main body 1 defined by a respective bushings 14.In this manner, tensioning pins 9 and thus also toolholders 5 arecentered in tensioning holes 13.

Each tensioning pin 9 exhibits a thickened pull head 15 gripped frombehind by a retaining element (not shown) of a tensioning apparatus 16.Tensioning apparatus 16 is set in an expanded prolongation 17 oftensioning hole 13. This is an example of a pneumatically-operatedtensioning apparatus 16 like that known from the brochure "InnovativeDocking and Tensioning Systems" by CyTec Zylindertechnik GmbH andcommercially available. The retaining element gripping behind pull head15 of this type of tensioning apparatus 16 is a pneumatically-operatedcollet chuck that, when under tension, remains under tension withoutpressure. The means of pressure delivery to activate the tension andrelease of tensioning apparatus 16 are the channels 18 and 19terminating into a pressure-delivery coupling connector 20 on the faceof toolhead main body 1. Alternatively, channels 18 and 19 could alsorun through the drive shaft of the profile cutter, for example.

For this purpose, the exemplary embodiment depicted is provided with acommon connecting ring 21 for all tensioning apparatuses 16 of thetoolhead, which ring is mounted at its face side to toolhead main body 1and covers the terminations of channels 18 and 19. A supply outlet 23can be inserted with a pressure-sealed connection into a connecting hole22 of connecting ring 21. through which supply outlet 23 the pressuremeans necessary to actuate tensioning apparatus 16 is delivered andremoved. A pivotably-seated supporting ring 24 on the face of thetoolhead has a through-hole 25 through which supporting ring supplyoutlet 23 can be inserted up to connecting hole 22.

Each of the chopping teeth 2, 3 has a chopping edge 2a, 3a, and each ofthe planing tools includes a planing edge 4a. The chopping edge 2a is oflonger length than the planing edge 4a, as can be seen in FIG. 2. Also,the chopping edges 2a extend closer to the rear side 1b than do theplaning edges 4a. The chopping teeth 2 are spaced circumferentiallyapart, as are the planing teeth. The chopping teeth define a cuttingcircle of larger diameter than the planing edges, as is evident fromFIG. 2.

In the modified exemplary embodiment represented in FIG. 3pneumatically-operated tensioning apparatus 16 shown in FIG. 2 isreplaced by a staged bolt 26 inserted through a rear side 1b of the mainbody and into tensioning hole 13 and its prolongation 17, which stagedbolt exhibits a centering pin 27 protruding from the face of toolheadmain body 1. Toolholder 5 is screwed onto centering pin 27, whichextends centered into hole 8 of toolholder 5 by means of mounting screws12 of circular saw ring segment 4, wherein a spacer 27a is placed.

The exemplary embodiment shown in FIG. 4 differs from the exemplaryembodiment in FIG. 3 only in that in place of circular saw ring segment4, one or more planing teeth 4' is/are mounted on toolholder 5.

All of the exemplary embodiments shown allow toolholders 5 with attachedcircular saw ring segments 4 or planing teeth 4' and face chopping teeth2 to be quickly and easily replaced when worn out. To do so, tensioningapparatuses 16 are released-or mounting screws 12 are loosened for theembodiments in FIG. 3 or 4--allowing toolholder 5 with the worn tools tobe removed. New toolholder 5 bearing sharp pre-adjusted tools 2 and 4 or4' is mounted on toolhead main body 1, centered and placed under tensionsuch that the toolhead is immediately ready for use. All measuresnecessary to replace toolholder 5 can be carried out from the face sideof the toolhead.

The claims made in this application do not preclude the assertion ofadditional protection within the framework of the overall contents ofthe application. The references of the dependent claims refer toadditional embodiments of features of the main claim; but this does notrepresent a waiver of the assertion of independent protection forfeatures of the dependent claims. At any time during the applicationprocess, features revealed only in the description may also be used asfeatures significant for the invention to define the subject-matter ofthe application.

We claim:
 1. A toolhead for cutting wood workpieces comprising:a mainbody including a front side and a rear side spaced apart along an axisdisposed substantially perpendicularly to a direction of feed of woodworkpieces, the main body being rotatable about the axis as theworkpieces are fed adjacent the front side; a plurality of choppingteeth and a plurality of planing teeth arranged on the body to rotatetherewith, the chopping teeth including respective chopping edges, andthe planing teeth including respective planing edges,the chopping teethand the planing teeth being distributed circumferentially with respectto the axis, the chopping edges being of longer length than the planingedges and defining a cutting circle of larger diameter than the planingedges, the chopping edges extending closer to the rear side of the mainbody than do the planing edges; and a toolholder removably mounted onthe front side of the main body and carrying at least one of thechopping teeth and at least one of the planing teeth, whereby the atleast one chopping tooth and the at least one planing tooth areinstallable and removable together with respect to the main body.
 2. Thetoolhead according to claim 1 wherein the toolholder comprises a segmentof a ring.
 3. The toolhead according to claim 1 wherein the toolholderis ring-shaped.
 4. The toolhead according to claim 1 wherein the planingteeth comprise saw teeth.
 5. The toolhead according to claim 4 whereinthe toolholder is in the form of a ring segment and includes forward andrearward ends, a chopping tooth being mounted at the forward end.
 6. Thetoolhead according to claim 5 wherein the main body includes atensioning hole, a tensioning device mounted in the main body inalignment with the tensioning hole, a tensioning pin extending throughthe toolholder in a direction parallel to the axis of rotation andreceived in the tensioning hole and engaged by the tensioning device,and a fastener received in the tensioning pin for releasably mountingthe toolholder on the main body.
 7. The toolhead according to claim 6wherein the tensioning pin includes a pull head engaged by thetensioning device.
 8. The toolhead according to claim 7 furtherincluding channels formed in the main body for conducting fluid to andfrom the tensioning device for displacing the tensioning pin.
 9. Thetoolhead according to claim 5 wherein the fastener comprises a screw.10. The toolhead according to claim 9 further including a centering pinextending through the tensioning hole, the screw extending into thecentering pin.